I have the following devices in general:
1. Personal laptop
2. Company laptop
3. Desktop machine at work
4. Personal iPad (regular 2018 iPad)
I could tell you that the iPad I have cannot replace my laptops (both personal and company wise). IMO some of the reasons are not related to the fact that I don't have iPad Pro. Decide yourself if you agree with me.
Without further ado here are the reasons:
1. Small screen. My company laptop might be 14 inch but I can and I do indeed hook up two external monitors to work with. This is OK when you have mouse support and you can switch between monitors. As it is, this is not possible with the iPad.
2. Ergonomics. Without a stand I get neck and back pain if I work too much on my iPad. The screen is too small for long hours work.
3. Typing. This is somewhat related to the screen size. I don't find the on screen keyboard good enough and the hardware one is rather small for fast typing which I tend to do.
4. Lack of proper multitasking
- Multiple instances of the same app is something that I use regularly.
- Multi languages support - I often use different languages for the different apps I use. I cannot do this on an iPad
5. No easy option to share screen as first we need to pay for additional dongles, second again lack of mouse support negates the idea of extending the screen
6. No easy option to print from said iPad. I would not by Apple printer to print when I have laptops that are compatible with all sort of printers.
7. Lack of proper file system. I constantly have issues with unresponsive Files app. That might be because of the RAM management and the fact that my iPad has just 2 GB. Nevertheless I can tell you that 2 GB are not enough for the type of user I am. I open multiple tabs, multiple browser windows, lots of apps and all of this causes constant reloading. I do not like to wait in reloading. I prefer the laptop as I can easily go back to the apps without waiting.
8. I use primarily Windows machines (both at work and at home) and I do not find that the iPad plays nice with them. As a result I use the iPad as a digital notebook to sketch and brainstorm. For everything else I prefer to use my laptops.
9. Sharing files between computer and iPad is PITA. iTunes for Windows is a mess, but as a whole I dislike the closed and restricted approach that Apple offers. It just demotivates me to even attempt something.
I would not use the iPad for editing photos for two reasons:
1. No easy way to import said photos
2. No support for batch processing of photos. I use DxO software that considers my lens and camera and offers quite efficient initial batch processing that I prefer over iPad's apps for photo editing.